From 38a7a13ac6ed6bba2584def7d7121257eb85e051 Mon Sep 17 00:00:00 2001
From: Takashi Kokubun <takashikkbn@gmail.com>
Date: Sat, 17 Sep 2022 21:16:06 +0900
Subject: [PATCH] Auto-generate the release date on version.h from git
 CommitDate (#6382)

* Auto-generate the release date on version.h

from git CommitDate

* Generate revision.h on mswin
---
 common.mk            |  3 ++-
 tool/file2lastrev.rb | 10 ++++++++--
 tool/lib/vcs.rb      | 22 ++++++++++++++++++----
 tool/make-snapshot   |  2 +-
 version.h            | 13 +++++--------
 win32/Makefile.sub   |  2 ++
 win32/ifchange.bat   |  1 +
 7 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/common.mk b/common.mk
index ad492c0079..fb1b785534 100644
--- a/common.mk
+++ b/common.mk
@@ -1214,7 +1214,7 @@ $(BUILTIN_RB_INCS): $(top_srcdir)/tool/mk_builtin_loader.rb
 $(srcdir)/revision.h:
 $(srcdir)/revision.h$(gnumake:yes=-nongnumake):
 	$(Q)$(RM) $(@F)
-	$(Q)$(NULLCMD) > $@ || $(NULLCMD) > $(@F)
+	$(NULLCMD) > $(@F)
 
 revision.tmp::
 	$(Q) $(NULLCMD) > $@
@@ -8275,6 +8275,7 @@ load.$(OBJEXT): {$(VPATH)}vm_core.h
 load.$(OBJEXT): {$(VPATH)}vm_opts.h
 loadpath.$(OBJEXT): $(hdrdir)/ruby/ruby.h
 loadpath.$(OBJEXT): $(hdrdir)/ruby/version.h
+loadpath.$(OBJEXT): $(top_srcdir)/revision.h
 loadpath.$(OBJEXT): $(top_srcdir)/version.h
 loadpath.$(OBJEXT): {$(VPATH)}assert.h
 loadpath.$(OBJEXT): {$(VPATH)}backward/2/assume.h
diff --git a/tool/file2lastrev.rb b/tool/file2lastrev.rb
index 008e4b55e5..476437a995 100755
--- a/tool/file2lastrev.rb
+++ b/tool/file2lastrev.rb
@@ -66,7 +66,13 @@ OptionParser.new {|opts|
     new_vcs["."]
   end
 }
-exit unless vcs
+unless vcs
+  # Output only release_date when .git is missing
+  if @output == :revision_h
+    puts VCS.release_date(Time.now - 10) # same as make-snapshot
+  end
+  exit
+end
 
 @output =
   case @output
@@ -76,7 +82,7 @@ exit unless vcs
     }
   when :revision_h
     Proc.new {|last, changed, modified, branch, title|
-      vcs.revision_header(last, modified, branch, title, limit: @limit)
+      vcs.revision_header(last, modified, modified, branch, title, limit: @limit)
     }
   when :doxygen
     Proc.new {|last, changed|
diff --git a/tool/lib/vcs.rb b/tool/lib/vcs.rb
index 05d95061c4..d33d41dba1 100644
--- a/tool/lib/vcs.rb
+++ b/tool/lib/vcs.rb
@@ -95,6 +95,15 @@ class VCS
     opts
   end
 
+  def self.release_date(time)
+    t = time.utc
+    [
+      t.strftime('#define RUBY_RELEASE_YEAR %Y'),
+      t.strftime('#define RUBY_RELEASE_MONTH %-m'),
+      t.strftime('#define RUBY_RELEASE_DAY %-d'),
+    ]
+  end
+
   attr_reader :srcdir
 
   def initialize(path)
@@ -204,7 +213,8 @@ class VCS
     revision_handler(rev).short_revision(rev)
   end
 
-  def revision_header(last, modified = nil, branch = nil, title = nil, limit: 20)
+  # make-snapshot generates only release_date whereas file2lastrev generates both release_date and release_datetime
+  def revision_header(last, release_date, release_datetime = nil, branch = nil, title = nil, limit: 20)
     short = short_revision(last)
     if /[^\x00-\x7f]/ =~ title and title.respond_to?(:force_encoding)
       title = title.dup.force_encoding("US-ASCII")
@@ -225,10 +235,11 @@ class VCS
       title = title.dump.sub(/\\#/, '#')
       code << "#define RUBY_LAST_COMMIT_TITLE #{title}"
     end
-    if modified
-      t = modified.utc
+    if release_datetime
+      t = release_datetime.utc
       code << t.strftime('#define RUBY_RELEASE_DATETIME "%FT%TZ"')
     end
+    code += VCS.release_date(release_date)
     code
   end
 
@@ -386,7 +397,10 @@ class VCS
   end
 
   class GIT < self
-    register(".git") {|path, dir| File.exist?(File.join(path, dir))}
+    register(".git") do |path, dir|
+      File.exist?(File.join(path, dir)) &&
+        (`#{COMMAND} -v` rescue false) # make sure git command exists
+    end
     COMMAND = ENV["GIT"] || 'git'
 
     def cmd_args(cmds, srcdir = nil)
diff --git a/tool/make-snapshot b/tool/make-snapshot
index 02b5d182f5..22ae360c3e 100755
--- a/tool/make-snapshot
+++ b/tool/make-snapshot
@@ -347,7 +347,7 @@ def package(vcs, rev, destdir, tmp = nil)
   end
 
   File.open("#{v}/revision.h", "wb") {|f|
-    f.puts vcs.revision_header(revision)
+    f.puts vcs.revision_header(revision, modified)
   }
   version ||= (versionhdr = IO.read("#{v}/version.h"))[RUBY_VERSION_PATTERN, 1]
   version ||=
diff --git a/version.h b/version.h
index 7ce07104d1..46f14e3f14 100644
--- a/version.h
+++ b/version.h
@@ -13,13 +13,12 @@
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
 #define RUBY_PATCHLEVEL -1
 
-#define RUBY_RELEASE_YEAR 2022
-#define RUBY_RELEASE_MONTH 9
-#define RUBY_RELEASE_DAY 17
-
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"
 
+#ifndef RUBY_REVISION
+#include "revision.h"
+
 #ifndef TOKEN_PASTE
 #define TOKEN_PASTE(x,y) x##y
 #endif
@@ -38,6 +37,8 @@
 #define RUBY_RELEASE_DAY_STR STRINGIZE(RUBY_RELEASE_DAY)
 #endif
 
+#endif
+
 #ifdef RUBY_ABI_VERSION
 # define RUBY_ABI_VERSION_SUFFIX "+"STRINGIZE(RUBY_ABI_VERSION)
 #else
@@ -61,8 +62,4 @@
 #define RUBY_PATCHLEVEL_STR ""
 #endif
 
-#ifndef RUBY_REVISION
-# include "revision.h"
-#endif
-
 #endif /* RUBY_TOPLEVEL_VERSION_H */
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index 361af556cd..e802b80968 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -1244,6 +1244,8 @@ $(RCFILES): $(RBCONFIG) $(srcdir)/revision.h $(srcdir)/win32/resource.rb
 			-so_name=$(RUBY_SO_NAME) \
 			. $(icondirs) $(win_srcdir)
 
+$(srcdir)/revision.h: $(REVISION_H)
+
 update-benchmark-driver:
 	$(GIT) clone https://github.com/benchmark-driver/benchmark-driver $(srcdir)/benchmark/benchmark-driver || \
 	  $(GIT) -C $(srcdir)/benchmark/benchmark-driver pull origin master
diff --git a/win32/ifchange.bat b/win32/ifchange.bat
index c7db628a04..fb9ad27337 100755
--- a/win32/ifchange.bat
+++ b/win32/ifchange.bat
@@ -89,6 +89,7 @@ if exist %dest% (
     )
 )
 for %%I in (%1) do echo %%~I updated
+del /f %dest%
 copy %src% %dest% > nul
 del %src%